Liquid crystal alignment agent, liquid crystal alignment film and liquid crystal display element having thereof

ABSTRACT

The present invention relates to a liquid crystal alignment agent, a liquid crystal alignment film made by the liquid crystal alignment agent and a liquid crystal display element having the liquid crystal alignment film. The liquid crystal alignment agent includes a polymer composition (A) and a solvent (B). The polymer composition (A) is synthesized by reacting a mixture that includes a tetracarboxylic dianhydride component (a) and a diamine component (b). The aforementioned liquid crystal alignment agent has a better process stability, and the liquid crystal alignment film made by the liquid crystal alignment agent could improve the reliability of the liquid crystal display element.

RELATED APPLICATIONS

This application claims priority to Taiwan Application Serial Number102133933, filed on Sep. 18, 2013, which is herein incorporated byreference.

BACKGROUND

1. Field of Invention

The present invention relates to a liquid crystal alignment agent of avertical aligned liquid crystal display element. More particularly, theliquid crystal alignment agent includes polyamic acid or polyimide andsolvent.

2. Description of Related Art

There is a requirement of the wide view angle of the liquid crystaldisplay element, thus the requirements of the electrical properties anddisplay properties have become stricter. In wide view angle liquidcrystal display element, the vertical alignment liquid crystal displayelement is widely studied. For meeting better electrical properties anddisplay properties, liquid crystal alignment film becomes one of theimportant factors.

The liquid crystal alignment film of the vertical alignment liquidcrystal display element is used to regularly align the liquid crystalmolecules with a larger pretilt angle when the electrical field is notapplied. For producing the aforementioned liquid crystal alignment film,a liquid crystal alignment agent having polymers such as polyamic acidor polyimide is firstly coated on a surface of the substrate, beingsubjected to a thermal treatment and an alignment treatment.

JP Patent publication No. 2009-237545 discloses a polyamic acid polymerapplied to form a liquid crystal alignment film in a liquid crystaldisplay element. The polyamic acid polymer is obtained by polymerizing adiamine compound having a structure of formula (VII) and atetracarboxylic dianhydride compound:

in formula (VII), R^(I) and R^(III) are respectively an ether group, athioether group, an ester group or a thioester group, and it does notconsider a relative position of the ester group and the thioester group;R^(II) is a methylene group or an alkylene group of 2 to 10 carbons;R^(IV) is a single bond, a methylene group or an ethylene group; X is amonovalent steroid-containing group of 17 to 40 carbons.

The aforementioned liquid crystal alignment film can keep the liquidcrystal molecules at 86° of the high pretilt angle to achieve excellentliquid crystal alignment properties. However, when the polyamic acidpolymer of the prior art is subjected to the aligning treatment, theliquid crystal alignment agent easily be affected by the conditions ofthe aligning treatment, so as to lower the aligning ability of theliquid crystal alignment film, further decreasing the pretilt angleuniformity of liquid crystal molecules. Thus, the aforementioned priorart has a defect of process stability. In addition, when the liquidcrystal alignment film is applied in the liquid crystal display element,the liquid crystal display element has a defect of reliability after theliquid crystal display element is subjected to high temperature and highhumidity testing.

Accordingly, there is a need to improve the aforementioned disadvantagesfor meeting the requirements of the liquid crystal alignment agent.

SUMMARY

Therefore, an aspect of the present invention provides a liquid crystalalignment agent. The liquid crystal alignment agent comprises a polymercomposition (A) and a solvent (B).

Another aspect of the present invention provides a liquid crystalalignment film. The liquid crystal alignment film is formed by theaforementioned liquid crystal alignment agent.

A further aspect of the present invention provides a liquid crystaldisplay element. The liquid crystal display element includes theaforementioned liquid crystal alignment film.

According to the aforementioned aspects, the liquid crystal alignmentagent comprising the polymer composition (A) and the solvent (B) all ofwhich are described in details as follows.

Liquid Crystal Alignment Agent Polymer Composition (A)

The polymer composition (A) is selected from the group consisting ofpolyamic acid, polyimide, polyimide series block-copolymer and acombination thereof. The polyimide series block-copolymer is selectedfrom the group consisting of polyamic acid block-copolymer, polyimideblock-copolymer, polyamic acid-polyimide block-copolymer and acombination thereof.

The polyamic acid, polyimide, and polyimide series block-copolymer ofthe polymer composition (A) all synthesized by reacting a mixture thatincludes a tetracarboxylic dianhydride component (a) and a diaminecomponent (b). The tetracarboxylic dianhydride component (a), thediamine component (b) and a method of producing the polymer composition(A) all of which are described in details as follows.

Tetracarboxylic Dianhydride Component (a)

The tetracarboxylic dianhydride component (a) can be selected from thegroup consisting of an aliphatic tetracarboxylic dianhydride compound,an alicyclic tetracarboxylic dianhydride compound, an aromatictetracarboxylic dianhydride compound, the tetracarboxylic dianhydridecomponent (a) having a structure of formula (IV-1) to (IV-6) and thelike.

For example, the aliphatic tetracarboxylic dianhydride compound includesbut is not limited ethane tetracarboxylic dianhydride, butanetetracarboxylic dianhydride and the like.

For example, the alicyclic tetracarboxylic dianhydride compound includesbut is not limited 1,2,3,4-cyclobutane tetracarboxylic dianhydride,1,2-dimethyl-1,2,3,4-cyclobutane tetracarboxylic dianhydride,1,3-dimethyl-1,2,3,4-cyclobutane tetracarboxylic dianhydride,1,3-dichloro-1,2,3,4-cyclobutane tetracarboxylic dianhydride,1,2,3,4-tetramethyl-1,2,3,4-cyclobutane tetracarboxylic dianhydride,1,2,3,4-cyclopentane tetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 3,3′,4,4′-dicyclohexane tetracarboxylicdianhydride,cis-3,7-dibutylcycloheptyl-1,5-diene-1,2,5,6-tetracarboxylicdianhydride, 2,3,5-tricarboxy cyclopentyl acetic acid dianhydride,dicyclo[2.2.2]-octyl-7-ene-2,3,5,6-tetracarboxylic dianhydride and thelike.

For example, the aromatic tetracarboxylic dianhydride compound includesbut is not limited3,4-dicarboxy-1,2,3,4-tetrahydronaphthalene-1-succinic acid dianhydride,pyromellitic dianhydride, 2,2′,3,3′-benzophenone tetracarboxylicdianhydride, 3,3′,4,4′-benzophenone tetracarboxylic dianhydride,3,3′,4,4′-biphenylsulfone tetracarboxylic dianhydride,1,4,5,8-naphthalene tetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 3,3′,4,4′-diphenylethane tetracarboxylicdianhydride, 3,3′,4,4′-dimethyl diphenylsilane tetracarboxylicdianhydride, 3,3′,4,4′-tetraphenylsilane tetracarboxylic dianhydride,1,2,3,4-furan tetracarboxylic dianhydride, 2,3,3′,4′-biphenyl ethertetracarboxylic dianhydride, 3,3′,4,4′-biphenylether tetracarboxylicdianhydride, 4,4′-bis(3,4-dicarboxyphenoxy)diphenylsulfide dianhydride,2,3,3′,4′-biphenylsulfide tetracarboxylic dianhydride,3,3′,4,4′-biphenylsulfide tetracarboxylic dianhydride,4,4′-bis(3,4-dicarboxyphenoxyl)diphenylsulfone dianhydride,4,4′-bis(3,4-dicarboxyphenoxyl)diphenylpropane dianhydride,3,3′,4,4′-perfluoroisopropylidene diphenyl dicarboxylic dianhydride,2,2′3,3′-biphenyl tetracarboxylic dianhydride, 2,3,3′,4′-biphenyltetracarboxylic dianhydride, 3,3′,4,4′-biphenyl tetracarboxylicdianhydride, bis(phthalic acid)phenylphosphine oxide dianhydride,p-phenylene-bis(triphenyl phthalic acid)dianhydride,m-phenylene-bis(triphenylphthalic acid)dianhydride,bis(triphenylphthalic acid)-4,4′-diphenyl ether dianhydride,bis(triphenylphthalic acid)-4,4′-diphenyl methane dianhydride, ethyleneglycol-bis(anhydrotrimelitate), propyleneglycol-bis(anhydrotrimelitate), 1,4-butanediol bis(anhydrotrimelitate),1,6-hexyanediol bis(anhydrotrimelitate), 1,8-octanediolbis(anhydrotrimelitate),2,2-bis(4-hydroxyphenyl)propane-bis(anhydrotrimelitate),2,3,4,5-tetrahydro-furantetracarboxylic dianhydride,1,3,3a,4,5,9b-Hexahydro-5-(tetrahydro-2,5-dioxofuran-3-yl)naphtho[1,2-c]furan-1,3-dione,1,3,3a,4,5,9b-Hexahydro-5-methyl-5-(tetrahydro-2,5-dioxofuran-3-yl)naphtho[1,2-c]furan-1,3-dione,1,3,3a,4,5,9b-Hexahydro-5-ethyl-5-(tetrahydro-2,5-dioxofuran-3-yl)naphtho[1,2-c]furan-1,3-dione,1,3,3a,4,5,9b-Hexahydro-7-methyl-5-(tetrahydro-2,5-dioxofuran-3-yl)naphtho[1,2-c]furan-1,3-dione,1,3,3a,4,5,9b-Hexahydro-7-ethyl-5-(tetrahydro-2,5-dioxofuran-3-yl)naphtho[1,2-c]furan-1,3-dione,1,3,3a,4,5,9b-Hexahydro-8-methyl-5-(tetrahydro-2,5-dioxofuran-3-yl)naphtho[1,2-c]furan-1,3-dione,1,3,3a,4,5,9b-Hexahydro-8-ethyl-5-(tetrahydro-2,5-dioxofuran-3-yl)naphtho[1,2-c]furan-1,3-dione,1,3,3a,4,5,9b-Hexahydro-5,8-dimethyl-5-(tetrahydro-2,5-dioxofuran-3-yl)naphtho[1,2-c]furan-1,3-dione,5-(2,5-dioxotetrahydrofuran)-3-methyl-3-cyclohexene-1,2-dicarboxylicdianhydride and the like.

The tetracarboxylic dianhydride composition (a) having a structure offormula (IV-1) to (IV-6) all of which are showed as follows:

In formula (IV-5), A₁ is a divalent group having an aromatic group; r isan integer of 1 or 2; A₂ and A₃ can be the same or different, and A₂ andA₃ respectively are a hydrogen atom or alkyl group. Preferably, thetetracarboxylic dianhydride composition (a) having a structure offormula (IV-5) can be selected from the group consisting of a compoundhaving a structure of formula (IV-5-1) to (IV-5-3):

In formula (IV-6), A₄ is a divalent group having an aromatic group; A₅and A₆ can be the same or different, and A₅ and A₆ respectively are ahydrogen atom or alkyl. Preferably, the tetracarboxylic dianhydridecomposition (a) having a structure of formula (IV-6) can be selectedfrom the group consisting of the compound having a structure of formula(IV-6-1):

Preferably, the tetracarboxylic dianhydride composition (a) includes butis not limited 1,2,3,4-cyclobutane tetracarboxylic dianhydride,1,2,3,4-cyclopentane tetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentyl acetic acid dianhydride, 1,2,4,5-cyclohexane tetracarboxylicdianhydride, 3,4-dicarboxy-1,2,3,4-tetrahydronaphthalene-1-succinic aciddianhydride, pyromellitic dianhydride, 3,3′,4,4′-benzophenonetetracarboxylic dianhydride and 3,3′,4,4′-biphenylsulfonetetracarboxylic dianhydride. The aforementioned tetracarboxylicdianhydride composition (a) can be used alone or a combination two ormore.

Diamine Component (b)

The diamine component (b) includes at least one diamine compound (b-1)having a structure of formula (I), at least one diamine compound (b-2)having a structure of formula (II) and an other diamine compound (b-3).

Diamine Compound (b-1)

The diamine compound (b-1) has a following structure of formula (I):

in the formula (I), B₁ is an alkylene group of 1 to 12 carbons or ahalogenalkylene group of 1 to 12 carbons; B₂ is

B₃ is a steroid-containing group, an organic group having a structure offormula (I-1) or —B₄—B₅—B₆. B₄ is an alkylene group of 1 to 10 carbons,B₅ is

and B₆ is a steroid-containing group or an organic group having thestructure of formula (I-1):

in the formula (I-1), B₇ is a hydrogen atom, a fluoro atom or a methylgroup; B₈, B₉ and B₁₀ respectively are a single bond,

or an alkylene group of 1 to 3 carbons; B₁₁ is

and B₁₃ and B₁₄ respectively are a hydrogen atom, a fluorine atom or amethyl group; B₁₂ is a hydrogen atom, a fluorine atom, an alkyl group of1 to 12 carbons, a fluoroalkyl group of 1 to 12 carbons, an alkoxylgroup of 1 to 12 carbons, —OCH₂F, —OCHF₂ or —OCF₃; a is 1 or 2; b, c andd respectively are an integer of 0 to 4; e, f, and g respectively are aninteger of 0 to 3, and (e+f+g)≧1; i and j respectively are 1 or 2. Whena is more than 1, a plurality of B₇ is the same or different, and dittofor a plurality B₈, B₉, B₁₀, B₁₁, B₁₃ and B₁₄ respectively when b, c, d,e, i and j are more than 1.

For example, the diamine compound (b-1) includes1-cholesteryloxymethyl-2,4-diaminobenzene,2-cholesteryloxyethyl-2,4-diaminobenzene,3-cholesteryloxypropyl-2,4-diaminobenzene,4-cholesteryloxybutyl-2,4-diaminobenzene,1-cholesteryloxymethyl-3,5-diaminobenzene,2-cholesteryloxyethyl-3,5-diaminobenzene,3-cholesteryloxypropyl-3,5-diaminobenzene,4-cholesteryloxybutyl-3,5-diaminobenzene,1-(1-cholesteryloxy-1,1-difluoromethyl)-2,4-diaminobenzene,1-(2-cholesteryloxy-1,1,2,2-tetrafluoroethyl)-2,4-diaminobenzene,1-(3-cholesteryloxy-1,1,2,2,3,3-hexafluoropropyl)-2,4-diamino-benzene,1-(4-cholesteryloxy-1,1,2,2,3,3,4,4-octafluorobutyl)-2,4-diaminobenzene,1-(1-cholesteryloxy-1,1-difluoromethyl)-3,5-diaminobenzene,1-(2-cholesteryloxy-1,1,2,2-tetrafluoroethyl)-3,5-diaminobenzene,1-(3-cholesteryloxy-1,1,2,2,3,3-hexafluoropropyl)-3,5-diamino-benzene,1-(4-cholesteryloxy-1,1,2,2,3,3,4,4-octafluorobutyl)-3,5-diaminobenzene,1-cholestanyloxymethyl-2,4-diaminobenzene,2-cholestanyloxyethyl-2,4-diaminobenzene,3-cholestanyloxypropyl-2,4-diaminobenzene,4-cholestanyloxybutyl-2,4-diaminobenzene,1-cholestanyloxymethyl-3,5-diaminobenzene,2-cholestanyloxyethyl-3,5-diaminobenzene,3-cholestanyloxypropyl-3,5-diaminobenzene,4-cholestanyloxybutyl-3,5-diaminobenzene,1-(1-cholestanyloxy-1,1-difluoromethyl)-2,4-diaminobenzene,1-(2-cholestanyloxy-1,1,2,2-tetrafluoroethyl)-2,4-diaminobenzene,1-(3-cholestanyloxy-1,1,2,2,3,3-hexafluoropropyl)-2,4-diaminobenzene,1-(4-cholestanyloxy-1,1,2,2,3,3,4,4-octafluoropropyl)-2,4-diaminobenzene,1-(1-cholestanyloxy-1,1-difluoromethyl)-3,5-diaminobenzene,1-(2-cholestanyloxy-1,1,2,2-tetrafluoroethyl)-3,5-diaminobenzene,1-(3-cholestanyloxy-1,1,2,2,3,3-hexafluoropropyl)-3,5-diaminobenzene,1-(4-cholestanyloxy-1,1,2,2,3,3,4,4-octafluoropropyl)-3,5-diaminobenzene,3-(2,4-diaminophenylmethoxy)-4,4-dimethylcholestane,3-[2-(2,4-diaminophenyl) ethoxy]-4,4-dimethylcholestane,3-[3-(2,4-diaminophenyl)propoxy]-4,4-dimethylcholestane,3-[4-(2,4-diaminophenyl)butoxy]-4,4-dimethylcholestane,3-(3,5-diaminophenylmethoxy)-4,4-dimethylcholestane,3-[2-(3,5-diaminophenyl) ethoxy]-4,4-dimethylcholestane,3-[3-(3,5-diaminophenyl)propoxy]-4,4-dimethylcholestane,3-[4-(3,5-diaminophenyl)butoxy]-4,4-dimethylcholestane,3-[1-(2,4-diaminophenyl)-1,1-difluoromethoxy]-4,4-dimethylcholestane,3-[2-(2,4-diaminophenyl)-1,1,2,2-tetrafluoromethoxy]-4,4-dimethylcholestane,3-[3-(2,4-diaminophenyl)-1,1,2,2,3,3-hexafluoro-methoxy]-4,4-dimethylcholestane,3-[4-(2,4-diaminophenyl)-1,1,2,2,3,3,4,4-octafluoromethoxy]-4,4-dimethylcholestane,3-[1-(3,5-diaminophenyl)-1,1-difluoromethoxy]-4,4-dimethylcholestane,3-[2-(3,5-diaminophenyl)-1,1,2,2-tetrafluoromethoxy]-4,4-dimethylcholestane,3-[3-(3,5-diaminophenyl)-1,1,2,2,3,3-hexafluoromethoxy]-4,4-dimethylcholestane,3-[4-(3,5-diaminophenyl)-1,1,2,2,3,3,4,4-octafluoromethoxy]-4,4-dimethylcholestane,3-(2,4-diaminophenyl) methoxycholane-24-oic hexadecyl ester,3-[2-(2,4-diaminophenyl)ethoxy]cholane-24-oic hexadecyl ester,3-[3-(2,4-diaminophenyl)propoxy]cholane-24-oic hexadecyl ester,3-[4-(2,4-diaminophenyl)butoxy]cholane-24-oic hexadecyl ester,3-(3,5-diaminophenyl)methoxycholane-24-oic hexadecyl ester,3-[2-(3,5-diaminophenyl)ethoxy]cholane-24-oic hexadecyl ester,3-[3-(3,5-diaminophenyl)propoxy]cholane-24-oic hexadecyl ester,3-[4-(3,5-diaminophenyl)butoxy]cholane-24-oic hexadecyl ester,3-[1-(3,5-diaminophenyl)-1,1-difluoromethoxy]cholane-24-oic hexadecylester,3-[2-(3,5-diaminophenyl)-1,1,2,2-tetrafluoromethoxy]cholane-24-oichexadecyl ester,3-[3-(3,5-diaminophenyl)-1,1,2,2,3,3-hexafluoropropoxy]cholane-24-oichexadecyl ester,3-[4-(3,5-diaminophenyl)-1,1,2,2,3,3,4,4-octafluoropropoxy]cholane-24-oichexadecyl ester, 3-(3,5-diaminophenyl)methoxycholane-24-oic stearylester, 3-[2-(3,5-diaminophenyl)ethoxy]cholane-24-oic stearyl ester,3-[3-(3,5-diaminophenyl)propoxy]cholane-24-oic stearyl ester,3-[4-(3,5-diaminophenyl)butoxy]cholane-24-oic stearyl ester,3-[1-(3,5-diaminophenyl)-1,1-difluoromethoxy]cholane-24-oic stearylester,3-[2-(3,5-diaminophenyl)-1,1,2,2-tetrafluoromethoxy]cholane-24-oicstearyl ester,3-[3-(3,5-diaminophenyl)-1,1,2,2,3,3-hexafluoropropoxy]cholane-24-oicstearyl ester.3-[4-(3,5-diaminophenyl)-1,1,2,2,3,3,4,4-octafluoro-propoxy]cholane-24-oicstearyl ester or a diamine compound having a structure of formula (I-2)to (I-19):

The aforementioned diamine compound (b-1) having a structure of formula(I) can be used alone or a combination two or more.

Preferable, the diamine compound (b-1) having a structure of formula (I)includes 1-cholesteryloxymethyl-2,4-diaminobenzene,2-cholesteryloxyethyl-2,4-diaminobenzene,1-cholesteryloxymethyl-3,5-diaminobenzene,2-cholesteryloxyethyl-3,5-diaminobenzene,1-cholestanyloxymethyl-2,4-diaminobenzene,2-cholestanyloxyethyl-2,4-diaminobenzene,1-cholestanyloxymethyl-3,5-diaminobenzene,2-cholestanyloxyethyl-3,5-diaminobenzene or the diamine compound (b-1)having a structure of formula (I-2), (I-3), (I-10), (I-11), (I-12),(I-14), (I-16), (I-17) or (I-19).

Based on a total amount of the diamine composition (b) as 100 moles, anamount of the diamine compound (b-1) is 3 moles to 40 moles, preferablyis 4 moles to 35 moles, and more preferably is 5 moles to 30 moles.

Diamine Compound (b-2)

The diamine compound (b-2) has a following structure of formula (II):

in the formula (II), B₁₅ and B₁₇ respectively are

B₁₆ is an alkylene group of 2 to 10 carbons; and B₁₈ is asteroid-containing group or an organic group having a structure ofaforementioned formula (I-1).

For example, the diamine compound (b-2) includes following diaminecompound having a structure of formula (II-1) to (II-31):

in formula (II-24) to (II-31), p is an integer of 2 to 10, and q is aninteger of 2 to 9.

The aforementioned diamine compound (b-2) can be used alone or acombination two or more.

Preferably, the diamine compound (b-2) having a structure of formula(II) is the diamine compound having a structure of aforementionedformula (II-3), (II-5), (II-6), (II-8), (II-12), (II-17), (II-22),(II-28) or following formula (II-32) to (II-35):

Based on the total amount of the diamine component (b) as 100 moles, anamount of the diamine compound (b-2) is 10 moles to 40 moles, preferablyis 12 moles to 35 moles, and more preferably is 15 moles to 30 moles.

A molar ratio [(b-1)/(b-2)] of the aforementioned diamine compound (b-1)to the diamine compound (b-2) is 0.1 to 3, preferably is 0.2 to 2.8, andmore preferably is 0.3 to 2.5.

When the molar ratio of the diamine compound (b-1) to the diaminecompound (b-2) is 0.1 to 3, the liquid crystal alignment agent hasexcellent process stability.

When the liquid crystal alignment agent do not include theaforementioned diamine compound (b-1) or diamine compound (b-2), theliquid crystal alignment agent do not have good process stability, andwhen the liquid crystal alignment agent is applied in the liquid crystaldisplay element, the liquid crystal display element has poorreliability.

Other Diamine Compound (b-3)

The other diamine compound (b-3) includes but is not limited1,2-diaminoethane, 1,3-diaminopropane, 1,4-diaminobutane,1,5-diaminopentane, 1,6-diaminohexane, 1,7-diaminoheptane,1,8-diaminooctane, 1,9-diaminononane, 1,10-diaminodecane,4,4′-diaminoheptane, 1,3-diamino-2,2-dimethylpropane,1,6-diamino-2,5-dimethylhexane, 1,7-diamino-2,5-dimethylheptane,1,7-diamino-4,4-dimethylheptane, 1,7-diamino-3-methylheptane,1,9-diamino-5-methylnonane, 2,11-diaminododecane,1,12-diaminooctadecane, 1,2-bis(3-aminopropoxyl) ethane,4,4′-diaminodicyclohexylmethane,4,4′-diamino-3,3′-dimethyldicyclohexylamine, 1,3-diaminocyclohexane,1,4-diaminocyclohexane, isophoronediamine, tetrahydrodicyclopentadienediamine, tricyclo(6-2-1-0^(2,7))-undecenoyl dimethyldiamine,4,4′-methylenebis (cyclohexylamine), 4,4′-diaminodiphenylmethane,4,4′-diaminodiphenylethane, 4,4′-diaminodiphenylsulfone,4,4′-diaminobenzanilide, 4,4′-diaminodiphenylether,3,4′-diaminodiphenylether, 1,5-diaminonaphthalene,5-amino-1-(4′-aminophenyl-1,3,3-trimethylindane,6-amino-1-(4-aminophenyl)-1,3,3-trimethylindane,hexahydro-4,7-methanoindanylenedimethylenediamine,3,3′-diaminobenzophenone, 3,4′-diaminobenzophenone,4,4′-diamino-benzophenone, 2,2-bis[4-(4-aminophenoxy)phenyl]propane,2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane,2,2-bis(4-aminophenyl) hexafluoropropane,2,2-bis[4-(4-aminophenoxy)phenyl]sulfone,1,4-bis(4-aminophenoxyl)benzene, 1,3-bis(4-aminophenoxy)benzene,1,3-bis(3-aminophenoxyl)benzene,9,9-bis(4-aminophenyl)-10-hydroanthracene,9,10-bis(4-aminophenyl)anthracene, 2,7-diaminofluorene,9,9-bis(4-aminophenyl) fluorene, 4,4′-methylene-bis(2-chloroaniline),4,4′-(p-phenyleneisopropylene) bisaniline,4,4′-(m-phenyleneisopropylene)bisaniline,2,2′-bis[4-(4-amino-2-trifluoromethylphenoxy)phenyl]hexafluoropropane,4,4′-bis[(4-amino-2-trifluoro)phenoxy]octafluorophenyl benzene,5-[4-(4-n-pentylcyclohexyl)cyclohexyl]phenylmethylene-1,3-diaminobenzene,1,1-bis[4-(4-aminophenoxy) phenyl]-4-(4-ethylphenyl)cyclohexane, and theother diamine compound having a structure of formula (III-1) to(III-25):

In the formula (III-1), B₁₉ is

B₂₀ is a steroid-containing group, a trifluoro methyl group, a fluorogroup, an alkyl group of 2 to 30 carbons or an monovalentnitrogen-containing cyclic group derived from pyridine, pyrimidine,triazine, piperidine, piperazine and the like.

Preferably, the diamine compound having a structure of formula (III-1)is 2,4-diaminophenyl ethyl formate, 3,5-diaminophenyl ethyl formate,2,4-diaminophenyl propyl formate, 3,5-diaminophenyl propyl formate,1-dodecoxy-2,4-diaminobenzene, 1-hexadecoxy-2,4-diaminobenzene,1-octadecoxy-2,4-diaminobenzene or the diamine compound having astructure of formula (III-1-1) to (III-1-4):

in the formula (III-2), B₂₁ is

B₂₂ and B₂₃ is a divalent group of an alicyclic ring, an aromatic ringor a heterocyclic ring. B₂₄ is an alkyl group of 3 to 18 carbons, analkoxyl group of 3 to 18 carbons, a fluoroalkyl group of 1 to 5 carbons,a fluoroalkoxyl group of 1 to 5 carbons, a cyano group or a halogenatom.

Preferably, the other diamine compound having a structure of formula(III-2) is the diamine compound having a structure of formula (III-2-1)to (III-2-13):

in the formula (III-2-10) to (III-2-13), s is an integer of 3 to 12.

in the formula (III-3), B₂₅ is a hydrogen atom, an acyl group of 1 to 5carbons, an alkyl group of 1 to 5 carbons, an alkoxyl group of 1 to 5carbons, or a halogen atom. In every repeating unit, B₂₅ can be the sameor different. B₂₆ is an integer of 1 to 3.

The diamine compound having a structure of formula (III-3) preferably isselected from the group consisting of (1) when B₂₆ is 1, such asp-diaminobenzene, m-diaminobenzene, o-diaminobenzene, 2,5-diaminotolueneand the like; (2) when B₂₆ is 2, such as 4,4′-diaminobiphenyl,2,2′-dimethyl-4,4′-diaminobiphenyl, 3,3′-dimethyl-4,4′-diaminobiphenyl,3,3′-dimethoxy-4,4′-diaminobiphenyl, 2,2′-dichloro-4,4′-diaminobiphenyl,3,3′-dichloro-4,4′-diaminobiphenyl,2,2′,5,5′-tetrachloro-4,4′-diaminobiphenyl,2,2′-dichloro-4,4′-diamino-5,5′-dimethoxybiphenyl, 4,4′-diamino-2,2′-bis(trichloromethyl)biphenyl and the like; (3) when B₂₆ is 3, such as1,4-bis(4′-aminophenyl)benzene and the like, and more preferably isp-diaminobenzene, 2,5-diaminotoluene, 4,4′-diaminobiphenyl,3,3′-dimethoxy-4,4′-diaminobiphenyl or 1,4-bis(4′-aminophenyl)benzene.

In the formula (III-4), B₂₇ is an integer of 2 to 12.

In the formula (III-5), B₂₈ is an integer of 1 to 5. Preferably, theformula (III-5) is selected from 4,4′-diamino-diphenylsulfide.

In the formula (III-6), B₂₉ and B₃₁ can be the same or different, andB₂₉ and B₃₁ respectively are divalent group; B₃₀ is a divalentnitrogen-containing cyclic group derived from pyridine, pyrimidine,triazine, piperidine, piperazine and the like.

In the formula (III-7), B₃₂, B₃₃, B₃₄ and B₃₅ respectively can be thesame or different, and B₃₂, B₃₃, B₃₄ and B₃₅ respectively are an alkylgroup of 1 to 12 carbons. B₃₆ is an integer of 1 to 3, and B₃₇ is aninteger of 1 to 20.

In the formula (III-8), B₃₈ is —O— or a cyclohexylene. B₃₉ is —CH₂—. B₄₀is phenylene or cyclohexylene. B₄₁ is a hydrogen atom or a heptyl.

Preferably, the diamine compound having a structure of formula (III-8)is selected from the group consisting of the diamine compound having astructure of formula (III-8-1) to (III-8-2):

The other diamine compound having a structure of formula (III-9) to(III-25) are showed as follows:

in the formula (III-17) to (III-25), B₄₂ preferably is an alkyl group of1 to 10 carbons, or an alkoxyl group of 1 to 10 carbons. B₄₃ preferablyis a hydrogen atom, an alkyl group of 1 to 10 carbons, or an alkoxylgroup of 1 to 10 carbons.

Preferably, the other diamine compound (b-2) includes but is not limited1,2-diaminoethane, 4,4′-diaminodicyclohexylmethane,4,4′-diaminodiphenyl-methane, 4,4′-diaminodiphenylether,5-[4-(4-n-amylcyclohexyl)cyclohexyl]phenylmethylene-1,3-diamino benzene,1,1-bis[4-(4-aminophenoxy)phenyl]-4-(4-ethylphenyl)cyclohexane,2,4-diaminophenyl ethyl formate, the formula (III-1-1), the formula(III-1-2), the formula (III-2-1), the formula (III-2-11), the formula(III-8-1), p-diaminobenzene, m-diaminobenzene, or o-diaminobenzene.

Based on a total amount of the diamine compound (b) as 100 moles, anamount of the aforementioned other diamine compound (b-3) is 20 moles to87 moles, preferably is 30 moles to 84 moles, and more preferably is 40moles to 80 moles.

Method of Producing Polymer Composition (A)

Method of Producing Polyamic Acid

A mixture is dissolved in a solvent, and the mixture includes atetracarboxylic dianhydride compound (a) and a diamine compound (b). Apolycondensation reaction is performed at 0° C. to 100° C. After 1 hr to24 hrs, the aforementioned reacting solution is subjected to a reducedpressure distillation by an evaporator, or the aforementioned reactingsolution was poured into a great quantity poor solvent to obtain aprecipitate. Then, the precipitate is dried by a method of reducedpressure drying to produce polyamic acid.

Based on the diamine compound (b) as 100 moles, the amount of thetetracarboxylic dianhydride compound (a) preferably is 20 moles to 200moles, and more preferably is 30 moles to 120 moles.

The solvent used in the polycondensation reaction can be the same as ordifferent from the solvent in the liquid crystal alignment agent. Thesolvent used in the polycondensation reaction does not have any speciallimitations. The solvent needs to dissolve the reactant and the product.Preferably, the solvent includes but is not limited (1) aprotic solvent,such as N-methyl-2-pyrrolidinone (NMP), N,N-dimethylacetamide,N,N-dimethylformamide, dimethylsulfoxide, γ-butyrolactone,tetramethylurea, hexmethyl phosphoric acid triamino and the like; (2)phenolic solvent, such as m-cresol, xylenol, phenol, halogenated phenoland the like. Based on the mixture as 100 parts by weight, the amount ofthe solvent used in the polycondensation reaction preferably is 200 to2000 parts by weight, and more preferably is 300 to 1800 parts byweight.

Particularly, in the polycondensation reaction, the solvent can combinewith suitable poor solvent. The formed polyamic acid won't precipitatein the poor solvent. The poor solvent can be used alone or incombination of two or more, and the poor solvent includes but is notlimited (1) alcohols, such as methanol, ethanol, isopropanol,cyclohexanol, ethylene glycol, propylene glycol, 1,4-butanediol,triethyleneglycol and the like; (2) ketone, such as acetone, methylethyl ketone, methyl isobutyl ketone, cyclohexanone and the like; (3)ester, such as methyl acetate, ethyl acetate, butyl acetate, diethyloxalate, diethyl malonate, ethylene glycol monoethyl ether acetate andthe like; (4) ether, such as diethyl ether, ethylene glycol methylether, ethylene glycol ethyl ether, ethylene glycol n-propyl ether,ethylene glycol isopropyl ether, ethylene glycol n-butyl ether, ethyleneglycol dimethyl ether, diethylene glycol dimethyl ether and the like;(5) halohydrocarbon, such as dichloromethane, 1,2-dichloro ethane,1,4-dichloro butane, trichloroethane, chlorobenzene, m-dichlorobenzeneand the like; (6) hydrocarbon, such as tetrahydrofuran, hexane, heptane,octane, benzene, toluene, xylene and the like, or a combination thereof.Based on the diamine compound (b) as 100 parts by weight, the amount ofthe poor solvent preferably is 0 to 60 parts by weight, and morepreferably is 0 to 50 parts by weight.

Method of Producing polyimide

A mixture is dissolved in a solvent, and a polymerization reaction isperformed to form polyamic acid. The aforementioned mixture includes atetracarboxylic dianhydride compound (a) and a diamine compound (b).Then, polyamic acid is heated to subject a dehydration ring-closurereaction in the presence of a dehydrating agent and a catalyst. The amicacid group of the polyamic acid is converted to an imide group by thedehydration ring-closure reaction, that is to say imidization, so as toform polyimide.

The solvent used in the dehydration ring-closure reaction can be thesame as the solvent in the liquid crystal alignment agent and is notillustrated any more here. Based on polyamic acid as 100 parts byweight, the amount of the solvent used in the dehydration ring-closurereaction preferably is 200 to 2000 parts by weight, and more preferablyis 300 to 1800 parts by weight.

The operating temperature of the dehydration ring-closure reactionpreferably is 40° C. to 200° C. for getting a better imidization ratioof the polyamic acid. More preferably, the aforementioned temperature is40° C. to 150° C. When the operating temperature of the dehydrationring-closure reaction is lower than 40° C., the reaction is incomplete,thereby lowering the imidization ratio of the polyamic acid. However,when the operating temperature is higher than 200° C., theweight-average molecular weight of the polyimide is lower.

The imidization ratio of the polymer (A) is 30% to 80%, preferably is35% to 80%, and more preferably is 40% to 80%. When the imidizationratio of the polymer composition (A) is 30% to 80%, and the liquidcrystal alignment agent is applied in the liquid crystal displayelement, the liquid crystal display has excellent reliability.

The dehydrating agent used in the dehydration ring-closure reaction isselected from the group consisting of acid anhydride compound. Forexample, the acid anhydride compound is acetic anhydride, propionicanhydride, trifluoroacetic anhydride and the like. Based on the polyamicacid as 1 mole, the amount of the dehydrating agent is 0.01 mole to 20moles. The catalyst used in the dehydration ring-closure reaction isselected from (1) pyridine compound, such as pyridine,trimethylpyridine, dimethylpyridine and the like; (2) tertiary aminecompound, such as triethyl amine and the like. Based on the dehydratingagent as 1 mole, the amount of the catalyst is 0.5 mole to 10 moles.

Method of Producing Polylmide Series Block Copolymer

The polyimide series block-copolymer is selected from the groupconsisting of the polyamic acid block-copolymer, polyimideblock-copolymer, polyamic acid-polyimide block copolymer and acombination thereof.

Preferably, a starting material is firstly dissolved in a solvent, and apolycondensation reaction is performed to produce the polyimide seriesblock-copolymer. The starting material includes at least oneaforementioned polyamic acid and/or at least one aforementionedpolyimide, and the starting material further comprises a tetracarboxylicdianhydride compound (a) and a diamine compound (b).

The tetracarboxylic dianhydride compound (a) and the diamine compound(b) in the starting material are the same as the tetracarboxylicdianhydride compound (a) and the diamine compound (b) used in the methodof producing aforementioned polyamic acid. The solvent used in thepolycondensation reaction is the same as the solvent in the liquidcrystal alignment agent and is not illustrated any more here.

Based on the starting material as 100 parts by weight, the solvent usedin the polymerization reaction preferably is 200 to 2000 parts byweight, and more preferably is 300 to 1800 parts by weight. Theoperating temperature of the polymerization reaction preferably is 0° C.to 200° C., and more preferably is 0° C. to 100° C.

Preferably, the starting material includes but is not limited (1) twopolyamic acid having different terminal groups and different structures;(2) two polyimide having different terminal groups and differentstructures; (3) the polyamic acid and the polyimide that have differentterminal groups and different structures; (4) the polyamic acid, thetetracarboxylic dianhydride compound and the diamine compound, and thestructure of the at least one of the tetracarboxylic dianhydridecompound and the diamine compound is different from the structures ofthe tetracarboxylic dianhydride compound and the diamine compound thatare used to form the polyamic acid; (5) the polyimide, thetetracarboxylic dianhydride compound and the diamine compound, and thestructure of the at least one of the tetracarboxylic dianhydridecompound and the diamine compound is different from the structures ofthe tetracarboxylic dianhydride compound and the diamine compound thatare used to form the polyimide; (6) the polyamic acid, the polyimide,the tetracarboxylic dianhydride compound and the diamine compound, andthe structure of the at least one of the tetracarboxylic dianhydridecompound and the diamine compound is different from the structures ofthe tetracarboxylic dianhydride compound and the diamine compound thatare used to form the polyamic acid or the polyimide; (7) two polyamicacid, tetracarboxylic dianhydride compounds or diamine compounds, andthey have different structures; (8) two polyimide, tetracarboxylicdianhydride compounds or diamine compounds, and they have differentstructures; (9) two polyamic acid and a diamine compounds, and the twopolyamic acid have different structures and the terminal groups of thepolyamic acid are acetic anhydride groups; (10) two polyamic acid and atetracarboxylic dianhydride compound, and the two polyamic acid havedifferent structures and the terminal groups of the polyamic acid areamine groups; (11) two polyimide and a diamine compound, and the twopolyimide have different structures and the terminal groups of thepolyimide are acid anhydride groups; 12) two polyimide and atetracarboxylic dianhydride compound, and the two polyimide havedifferent structures and the terminal groups of the polyimide are aminegroups.

Preferably, the polyamic acid, the polyimide and the polyimide blockcopolymer can be terminal-modified polymer after adjusting the molecularweight without departing from the efficiency of the present invention.The terminal-modified polymer can improve a coating ability of theliquid crystal alignment agent. When the polymerization reaction of thepolyamic acid is performed, a compound having a monofunctional group isadded to produce the terminal-modified polymer. The monofunctional groupincludes but is not limited (1) monoacid anhydride, such as maleicanhydride, phthalic anhydride, itaconic anhydride, n-decyl succinicanhydride, n-dodecyl succinic anhydride, n-tetradecyl succinicanhydride, n-hexadecyl succinic anhydride and the like; (2) monoaminecompound, such as aniline, cyclohexaylamine, n-butylamine,n-pentylamine, n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine,n-decylamine, n-undecylamine, n-dodecylamine, n-tridecylamine,n-tetradecylamine, n-pentadecylmaine, n-hexadecylamine,n-heptadecylamine, n-octadecylamine, n-eicosylamine and the like; (3)monoisocyanate compound, such as phenyl isocyanate, naphthyl isocyanateand the like.

Solvent (B)

Preferably, the solvent (B) is N-methyl-2-pyrrolidone, γ-butyrolactone,γ-butyrolactam, 4-hydroxyl-4-methyl-2-pentanone, ethylene glycolmonomethyl ether, butyl lactate, butyl acetate, methylmethoxypropionate,ethylethoxypropionate, ethylene glycol methyl ether, ethylene glycolethyl ether, ethylene glycol n-propyl ether, ethylene glycol isopropylether, ethylene glycol n-butyl ether, ethylene glycol dimethyl ether,ethylene glycol ethyl ether acetate, diglycol dimethyl ether, diglycoldiethyl ether, diglycol monomethyl ether, diglycol monoethyl ether,diglycol monomethyl ether acetate, diglycol monoethyl ether acetate,N,N-dimethylformamide, N,N-dimethylethanamide and the like. The solvent(B) can be used alone or in combination of two or more.

Additive (C)

The liquid crystal alignment agent can selectively include an additive(C) without departing from the efficiency of the present invention. Theadditive (C) is an epoxy compound or a functional group-containingsilane compound. The additive (C) can raise the adhesion between theliquid crystal alignment film and the surface of the substrate. Theadditive (C) can be used alone or in combination of two or more.

The epoxy compound includes but is not limited ethylene glycoldiglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycoldiglycidyl ether, tripropylene glycol diglycidyl ether, polypropyleneglycol diglycidyl ether, neopentyl glycol diglycidyl ether,1,6-hexanediol diglycidyl ether, 2,2-dibromo-neopentyl diglycidyl ether,1,3,5,6-tetraglycidyl-2,4-hexanediol, N,N,N′,N′-tetraglycidyl-m-xylenediamine, 1,3-bis(N,N-diglycidylaminomethyl) cyclohexane,N,N,N′,N′-tetraglycidyl-4,4′-diaminodiphenylmethane,N,N-glycidyl-p-glycidoxy aniline,3-(N-allyl-N-glycidyl)aminopropyltrimethoxyl silane,3-(N,N-diglycidyl)aminopropyl trimethoxyl silane and the like.

Based on the polymer (A) as 100 parts by weight, the amount of the epoxycompound is less than 40 parts by weight, and preferably is 0.1 parts byweight to 30 parts by weight.

The functional group-containing silane compound includes but is notlimited to 3-aminopropyl trimethoxy silane,3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane,2-aminopropyltriethoxysilane,N-(2-aminoethyl)-3-aminopropyltrimethoxysilane,N-(2-aminoethyl)-3-aminopropylmethyl-dimethoxysilane,3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane,N-ethoxycarbonyl-3-aminopropyltrimethoxysilane,N-ethoxycarbonyl-3-aminopropyltriethoxysilane,N-triethoxysilylpropyltriethylene triamine,N-trimethoxysilylpropyltriethylenetriamine,10-trimethoxysilyl-1,4,7-triazadecane,10-triethoxysilyl-1,4,7-triazadecane,9-trimethoxysilyl-3,6-diazanonylacetate,9-triethoxysilyl-3,6-diazanonylacetate,N-benzyl-3-aminopropyltrimethoxysilane,N-benzyl-3-aminopropyltriethoxysilane,N-phenyl-3-aminopropyl-trimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane, N-bis(oxyethylene)-3-aminopropyltrimethoxysilane,N-bis(oxyethylene)-3-aminopropyl-triethoxysilane and the like.

Based on the polymer (A) as 100 parts by weight, the amount of thesilane-containing compound is less than 10 parts by weight, andpreferably is 0.5 parts by weight to 10 parts by weight.

Producing Liquid Crystal Alignment Agent

The liquid crystal alignment agent of the present invention is producedby a conventional mixing method. For example, the tetracarboxylicdianhydride compound (a) and the diamine compound (b) are mixeduniformly to produce the polymer (A). Then, the polymer (A) is added tothe solvent (B) at 0° C. to 200° C. in a mixer until all compositionsare mixed uniformly, and the additive (C) is selectively added.Preferably, the solvent (B) is added into the polymer (A) at 20° C. to60° C.

Preferably, at 25° C., a viscosity of the liquid crystal alignment agentis 15 cps to 35 cps, preferably is 17 cps to 33 cps, and more preferablyis 20 cps to 30 cps.

Producing Liquid Crystal Alignment Film

The producing method of the liquid crystal alignment film comprises thefollowing steps. The aforementioned liquid crystal alignment agentfirstly is coated on a surface of a substrate to form a coating film bya roller coating, a spin coating, a printing coating, an ink-jetprinting and the like. Then, a pre-bake treatment, a post-bake treatmentand an alignment treatment are subject to the coating film to producethe liquid crystal alignment film.

The organic solvent in the coating film is volatilized by theaforementioned pre-bake treatment. The operating temperature of thepre-bake treatment is 30° C. to 120° C., preferably is 40° C. to 110°C., and more preferably is 50° C. to 100° C.

The alignment treatment does not have any limitations. The liquidcrystal alignment film is rubbed along a desired direction with a rollerthat is covered with a cloth made from fibers such as nylon, rayon,cotton and the like. The aforementioned alignment treatment is widelyknown rather than focusing or mentioning them in details.

The polymer in the coating film is further subjected to the dehydrationring-closure (imidization) reaction by the post-bake treatment. Theoperating temperature of the post-bake treatment is 150° C. to 300° C.,preferably is 180° C. to 280° C., and more preferably is 200° C. to 250°C.

Producing Method of Liquid Crystal Display Element

The producing method of the liquid crystal display element is widelyknown rather than focusing or mentioning them in details.

Reference is made to FIG. 1, which is a cross-sectional diagram of aliquid crystal display element according to the present invention. In apreferable example, the liquid crystal display element 100 includes afirst unit 110, a second unit 120 and a liquid crystal unit 130. Thesecond unit 120 is spaced apart opposite the first unit 110, and theliquid crystal unit 130 is disposed between the first unit 110 and thesecond unit 120.

The first unit 110 includes a first substrate 111, a first conductivefilm 113 and a first liquid crystal alignment film 115. The firstconductive film 113 is disposed on a surface of the first substrate 111,and the first liquid crystal alignment film 115 is disposed on a surfaceof the first conductive film 113.

The second unit 120 includes a second substrate 121, a second conductivefilm 123 and a second liquid crystal alignment film 125. The secondconductive film 123 is disposed on a surface of the second substrate121, and the second liquid crystal alignment film 125 is disposed on asurface of the second conductive film 123.

The first substrate 111 and the second substrate 121 are selected from atransparent material and the like. The transparent material includes butis not limited an alkali-free glass, a soda-lime glass, a hard glass(Pyrex glass), a quartz glass, polyethylene terephthalate, polybutyleneterephthalate, polyethersulfone, polycarbonate and the like. Thematerials of the first conductive film 113 and the second conductivefilm 123 are selected from tin oxide (SnO₂), indium oxide-tin odide(In₂O₃—SnO₂) and the like.

The first liquid crystal alignment film 115 and the second liquidcrystal alignment film 125 respectively are the aforementioned liquidcrystal alignment films, which can provide the liquid crystal unit 130with a pretilt angle. The liquid crystal unit 130 is driven by anelectric field induced by the first conductive film 113 and the secondconductive film 123.

A liquid crystal material used in the liquid crystal unit 130 can beused alone or in combination of two or more. The liquid crystal materialincludes but is not limited diaminobenzene liquid crystal, pyridazineliquid crystal, Shiff Base liquid crystal, azoxy liquid crystal,biphenyl liquid crystal, phenyl cyclohexane liquid crystal, ester liquidcrystal, terphenyl liquid crystal, biphenyl cyclohexane liquid crystal,pyrimidine liquid crystal, dioxane liquid crystal, bicyclooctane liquidcrystal, cubane liquid crystal and the like. Optionally, the liquidcrystal material includes cholesterol liquid crystal, such ascholesteryl chloride, cholesteryl nonanoate, cholesteryl carbonate andthe like; chiral agent, such as products made by Merck Co. Ltd., and thetrade name are C-15 and CB-15; ferroelectric liquid crystal, such asp-decoxyl benzilidene-p-amino-2-methyl butyl cinnamate and the like.

Several embodiments are described below to illustrate the application ofthe present invention. However, these embodiments are not used forlimiting the present invention. For those skilled in the art of thepresent invention, various variations and modifications can be madewithout departing from the spirit and scope of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention can be more fully understood by reading the followingdetailed description of the embodiment, with reference made to theaccompanying drawings as follows:

FIG. 1 is a cross-sectional diagram of a liquid crystal display elementaccording to the present invention.

DETAILED DESCRIPTION Producing Polymer Composition (A)

The polymer composition (A) of Synthesis Examples A-1-1 to A-2-10 andComparative Synthesis Examples A-3-1 to A-3-6 were according to Table 1and Table 2 as follows.

Synthesis Example A-1-1

A 500 ml four-necked conical flask equipped with a nitrogen inlet, astirrer, a condenser and a thermometer was purged with nitrogen. Then,1.97 g (0.005 mole) of the diamine compound (b-1-1) having a structureof formula (I-11), 4.84 g (0.01 mole) of the diamine compound (b-2-1)having a structure of formula (II-33), 3.78 g (0.035 mole) ofp-diaminobenzene (b-3-1) and 80 g of N-methyl-2-pyrrolidinone were mixeduniformly at room temperature. Next, 10.91 g (0.05 mole) of pyromelliticdianhydride (a-1) and 20 g of N-methyl-2-pyrrolidinone were added andleft to react for 2 hours at room temperature. When the reaction iscompleted, the reacting solution was poured into 1500 ml of water toprecipitate the polymer. The polymer obtained after filtering wasrepeatedly washed using methanol and filtered thrice, and then placedinto a vacuum oven, where drying was carried out at 60° C., therebyobtaining a polymer composition (A-1-1). An imidization ratio of theresulted polymer composition (A-1-1) was evaluated according to thefollowing evaluation method, and the result thereof was listed asTable 1. The evaluation method of the imidization ratio was described asfollows.

Synthesis Examples A-1-2 to A-1-5 and Comparative Synthesis ExampleA-3-1

Synthesis Examples A-1-2 to A-1-5 and Comparative Synthesis ExampleA-3-1 were practiced with the same method as in Synthesis Example A-1-1by using various kinds or amounts of the components for the polymercomposition. The formulations and detection results thereof were listedin Table 1 and Table 2 rather than focusing or mentioning them indetails.

Synthesis Example A-2-1

A 500 ml four-necked conical flask equipped with a nitrogen inlet, astirrer, a heater, a condenser and a thermometer was purged withnitrogen. Then, 1.97 g (0.005 mole) of the diamine compound (b-1-1)having a structure of formula (I-11), 4.84 g (0.001 mole) of the diaminecompound (b-2-1) having a structure of formula (II-33), 3.78 g (0.035mole) of p-diaminobenzene (b-3-1) and 80 g of N-methyl-2-pyrrolidinonewere mixed uniformly at room temperature. Next, 10.91 g (0.05 mole) ofpyromellitic dianhydride and 20 g of N-methyl-2-pyrrolidinone were addedand left to react for 6 hours at room temperature. And then, 97 g ofN-methyl-2-pyrrolidinone, 2.55 g of acetic anhydride and 19.75 g ofpyridine were added at 60° C. and left to stir for 2 hours forimidization reaction. When the reaction is completed, the reactingsolution was poured into 1500 ml of water to precipitate the polymer.The polymer obtained after filtering was repeatedly washed usingmethanol and filtered thrice, and then placed into a vacuum oven, wheredrying was carried out at 60° C., thereby obtaining a polymercomposition (A-2-1). An imidization ratio of the resulted polymercomposition (A-2-1) was evaluated according to the following evaluationmethod, and the result thereof was listed as Table 1.

Synthesis Examples A-2-2 to A-2-10 and Comparative Synthesis ExamplesA-3-2 to A-3-6

Synthesis Examples A-2-2 to A-2-10 and Comparative Synthesis ExamplesA-3-2 to A-3-6 were practiced with the same method as in SynthesisExample A-2-1 by using various kinds or amounts of the compositions forthe polyimide. The formulations and detection results thereof werelisted in Table 1 and Table 2 rather than focusing or mentioning them indetails.

Producing Liquid Crystal Alignment Agent

Hereinafter, the liquid crystal alignment agents of Examples 1 to 15 andComparative Examples 1 to 6 were according to Table 3 and Table 4 asfollows.

Example 1

100 parts by weight of the polymer (A-1-1) was added into 1200 parts byweight of N-methyl-2-pyrrolidinone (hereinafter abbreviated as B-1) and600 parts by weight of ethylene glycol n-butyl ether (hereinafterabbreviated as B-2) for mixing in a mixer until all compounds were mixeduniformly at room temperature, thereby obtaining the liquid crystalalignment agent of Example 1. The resulted liquid crystal alignmentagent was evaluated according to the following evaluation method, andthe result thereof was listed as Table 3. The evaluation methods of theprocess stability and reliability were described as follows.

Examples 2 to 15 and Comparative Examples 1 to 6

Examples 2 to 15 and Comparative Examples 1 to 6 were practiced with thesame method as in Example 1 by using various kinds or amounts of thecompositions for the liquid crystal alignment agent. The formulationsand detection results thereof were listed in Table 2 and Table 4 ratherthan focusing or mentioning them in details.

Evaluation Methods 1. Imidization Ratio

The imidization ratio refers to a ratio of the number of imide ring inthe total amount of the number of amic acid functional group and thenumber of imide ring in the polymer composition (A), and the imidizationratio is presented by percentage.

After the aforementioned method of reduced pressure drying is performed,the polymer composition (A) of Synthesis Examples A-1-1 to A-2-10 andComparative Synthesis Examples A-3-1 to A-3-6 respectively weredissolved in a suitable deuteration solvent, such as deuterated dimethylsulfoxide. ¹H-NMR (hydrogen-nuclear magnetic resonance) was detected atroom temperature (25° C.) using tetramethylsilane as a standard, and theimidization ratio (%) was calculated according to the following formula(V):

$\begin{matrix}{{{Imidization}\mspace{14mu} {Ratio}\mspace{14mu} (\%)} = {\lbrack {1 - \frac{\Delta \; 1}{\Delta \; 2 \times \alpha}} \rbrack \times 100\%}} & (V)\end{matrix}$

in the formula (V), Δ1 is the peak area of the chemical shift induced bythe proton of NH group near 10 ppm, Δ2 is the peak area of other proton,and α is the ratio of one proton of NH group corresponding to the numberof other proton in the polyamic acid precursor.

2. Process Stability

The liquid crystal alignment films were respectively made by the liquidcrystal alignment agents of the aforementioned Examples 1 to 15 and theComparative Examples 1 to 6, and the liquid crystal display elementshaving the same were fabricated. In the process for producing the liquidcrystal display elements, the liquid crystal display element wassubjected to a pre-bake treatment with 80° C., 90° C., 100° C., 110° C.and 120° C., thereby obtaining five liquid crystal display elements. Andthen, a pretilt angle uniformity (P) was detected. The variation of thepretilt angle uniformity (P) was calculated according to the followingformula (VI), and an evaluation was made according to the followingcriterion:

the variation of P=(P _(max) −P _(min))×100%  (IV)

-   -   ⊚: the variation of P≦2%    -   ◯: 2%<the variation of P≦5%    -   Δ: 5%<the variation of P≦10%    -   X: 10%<the variation of P

3. Reliability

The liquid crystal films were respectively made by the liquid crystalalignment agents of the aforementioned Examples 1 to 15 and theComparative Examples 1 to 6, and the liquid crystal display elementshaving the same were fabricated. Next, the liquid crystal displayelements of Examples 1 to 15 and the Comparative Examples 1 to 6 wererespectively disposed in an environment with 65° C. and 85% of relativehumidity to subjecting to a reliability testing. After 120 hours,voltage holding ratios of the liquid crystal display elements wererespectively detected by an electrical measuring machine (manufacturedby TOYO Corporation, and the trade name is Model 6254). A voltage of 4volts was applied for 2 milliseconds. The applied voltage was held for1667 milliseconds. After the applied voltage was cut off for 1667milliseconds, the voltage holding ratio was measured, and an evaluationwas made according to the following criterion:

-   -   ⊚: 94%≦voltage holding ratio    -   ∘: 92%≦voltage holding ratio<94%    -   Δ: 90%≦voltage holding ratio<92%    -   X: voltage holding ratio≦90%

According to Table 3 and Table 4, when the liquid crystal alignmentagent simultaneously includes the diamine compound (b-1) and the diaminecompound (b-2), the liquid crystal alignment agent has well processstability, and when the liquid crystal alignment agent is applied in theliquid crystal display element, the liquid crystal display element hasexcellent reliability.

Moreover, when the molar ratio [(b-1)/(b-2)] of the diamine compound(b-1) to the diamine compound (b-2) is 0.1 to 3, the liquid crystalalignment agent has excellent process stability.

Furthermore, when the imidization ratio of the polymer composition (A)is 30% to 80%, the liquid crystal alignment film made by the liquidcrystal alignment agent can improve the reliability of the liquidcrystal display element.

It should be supplemented that, although specific compounds, components,specific reactive conditions, specific processes, specific evaluationmethods or specific equipments are employed as exemplary embodiments ofthe present invention, for illustrating the liquid crystal alignmentagent, the liquid crystal alignment film and the liquid crystal displayelement having thereof of the present invention. However, as isunderstood by a person skilled in the art instead of limiting to theaforementioned examples, the liquid crystal alignment agent, the liquidcrystal alignment film and the liquid crystal display element havingthereof of the present invention also can be manufactured by using othercompounds, components, reactive conditions, processes, analysis methodsand equipment without departing from the spirit and scope of the presentinvention.

As is understood by a person skilled in the art, the foregoing preferredembodiments of the present invention are illustrated of the presentinvention rather than limiting of the present invention. In view of theforegoing, it is intended to cover various modifications and similararrangements included within the spirit and scope of the appendedclaims. Therefore, the scope of which should be accorded the broadestinterpretation so as to encompass all such modifications and similarstructure.

TABLE 1 Synthesis Example Composition(mole %) A-1-1 A-1-2 A-1-3 A-1-4A-1-5 A-2-1 A-2-2 A-2-3 Tetracarboxylic a-1 100 100 100 Dianhydride a-2100 50 100 Component (a) a-3 100 50 100 Diamine Diamine b-1-1 10 10Component Compound b-1-2 30 30 (b) (b-1) b-1-3 3 3 b-1-4 40 b-1-5 4Diamine b-2-1 20 12 20 Compound b-2-2 10 20 10 (b-2) b-2-3 40 40 b-2-420 Diamine b-3-1 70 8 70 Compound b-3-2 60 56 60 (b-3) b-3-3 57 40 57Molar Ratio of (b-1)/(b-2) 0.50 3.00 0.08 3.33 0.10 0.50 3.00 0.08Imidization Ratio(%) 0 0 0 0 0 13 22 28 Synthesis ExampleComposition(mole %) A-2-4 A-2-5 A-2-6 A-2-7 A-2-8 A-2-9 A-2-10Tetracarboxylic a-1 100 50 100 Dianhydride a-2 50 100 50 80 Component(a) a-3 50 100 20 Diamine Diamine b-1-1 10 30 Component Compound b-1-2(b) (b-1) b-1-3 5 20 10 b-1-4 40 20 5 b-1-5 4 Diamine b-2-1 12 25 10Compound b-2-2 20 30 10 (b-2) b-2-3 25 b-2-4 20 5 Diamine b-3-1 8 40 55Compound b-3-2 56 40 50 75 (b-3) b-3-3 40 30 6 Molar Ratio of(b-1)/(b-2) 3.33 0.10 0.20 1.00 0.80 2.00 1.50 Imidization Ratio(%) 3043 51 64 80 86 93 a-1-1 2,3,5-tricarboxy cyclopentyl acetic aciddianhydride a-1-2 1,2,3,4-cyclobutane tetracarboxylic dianhydride a-1-3pyromellitic dianhydride b-1-1 diamine compound having a structure offormula (I-11) b-1-2 diamine compound having a structure of formula(I-19) b-1-3 diamine compound having a structure of formula (I-14) b-1-4diamine compound having a structure of formula (I-10) b-1-5 diaminecompound having a structure of formula (I-3) b-2-1 diamine compoundhaving a structure of formula (II-33) b-2-2 diamine compound having astructure of formula (II-32) b-2-3 diamine compound having a structureof formula (II-3) b-2-4 diamine compound having a structure of formula(II-6) b-3-1 p-diaminobenzene b-3-2 4,4′-diaminodiphenylmethane b-3-34,4′-diaminodiphenylether

TABLE 2 Comparative Synthesis Example Composition(mole %) A-3-1 A-3-2A-3-3 A-3-4 A-3-5 A-3-6 Tetracarboxylic a-1 100 100 100 Dianhydride a-2100 100 Component (a) a-3 100 Diamine Diamine b-1-1 Component Compoundb-1-2 30 (b) (b-1) b-1-3 20 b-1-4 b-1-5 5 Diamine b-2-1 20 Compoundb-2-2 (b-2) b-2-3 25 b-2-4 Diamine b-3-1 80 44 55 95 Compound b-3-2 7056 45 25 (b-3) b-3-3 30 Molar Ratio of (b-1)/(b-2) 0.00 — — 0.00 — 0.00Imidization Ratio(%) 0 22 43 51 80 49 a-1-1 2,3,5-tricarboxy cyclopentylacetic acid dianhydride a-1-2 1,2,3,4-cyclobutane tetracarboxylicdianhydride a-1-3 pyromellitic dianhydride b-1-1 diamine compound havinga structure of formula (I-11) b-1-2 diamine compound having a structureof formula (I-19) b-1-3 diamine compound having a structure of formula(I-14) b-1-4 diamine compound having a structure of formula (I-10) b-1-5diamine compound having a structure of formula (I-3) b-2-1 diaminecompound having a structure of formula (II-33) b-2-2 diamine compoundhaving a structure of formula (II-32) b-2-3 diamine compound having astructure of formula (II-3) b-2-4 diamine compound having a structure offormula (II-6) b-3-1 p-diaminobenzene b-3-2 4,4′-diaminodiphenylmethaneb-3-3 4,4′-diaminodiphenylether

TABLE 3 Composition Example (Parts by Weight) 1 2 3 4 5 6 7 8 9 10 11 1213 14 15 Polymer A-1-1 100 Composition A-1-2 100 (A) A-1-3 100 A-1-4 100A-1-5 100 A-2-1 100 A-2-2 100 A-2-3 100 A-2-4 100 A-2-5 100 A-2-6 100A-2-7 100 A-2-8 100 A-2-9 100 50 A-2-10 50 A-3-1 A-3-2 A-3-3 A-3-4 A-3-5A-3-6 Solvent B-1 1200 800 1000 900 850 1400 400 800 1200 (B) B-2 6001600 800 1500 850 1000 400 750 1200 600 B-3 1000 800 700 600 350 1600400 250 Additive C-1 5 3 (C) C-2 10 5 2 Evaluation Process ⊚ ⊚ ◯ ◯ ⊚ ⊚ ⊚◯ ◯ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ Method stability Reliability ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ⊚ ⊚ ⊚ ⊚ ⊚ ◯◯ B-1 N-methyl-2-pyrrolidinone B-2 ethylene glycol n-butyl ether B-3N,N-dimethylacetamide C-1N,N,N′,N′-tetraglycidyl-4,4′-diaminodiphenylmethane C-2N,N-glycidyl-p-glycidoxy aniline

TABLE 4 Composition Comparative Example (Parts by Weight) 1 2 3 4 5 6Polymer A-1-1 Composition A-1-2 (A) A-1-3 A-1-4 A-1-5 A-2-1 A-2-2 A-2-3A-2-4 A-2-5 A-2-6 A-2-7 A-2-8 A-2-9 A-2-10 A-3-1 100 A-3-2 100 A-3-3 100A-3-4 100 A-3-5 100 A-3-6 100 Solvent B-1 1200 1400 785 (B) B-2 600 8001600 1000 785 B-3 800 350 Additive C-1 (C) C-2 10 Evaluation Process X XX X X X Method stability Reliability X X X X X X B-1N-methyl-2-pyrrolidinone B-2 ethylene glycol n-butyl ether B-3N,N-dimethylacetamide C-1N,N,N′,N′-tetraglycidyl-4,4′-diaminodiphenylmethane C-2N,N-glycidyl-p-glycidoxy aniline

What is claimed is:
 1. A liquid crystal alignment agent, comprising: apolymer composition (A), synthesized by reacting a mixture that includesa tetracarboxylic dianhydride component (a) and a diamine component (b);and a solvent (B); and wherein the diamine component (b) includes atleast one diamine compound (b-1) having a structure of formula (I), atleast one diamine compound (b-2) having a structure of formula (II) andan other diamine compound (b-3):

in the formula (I), B₁ is an alkylene group of 1 to 12 carbons or ahalogenalkylene group of 1 to 12 carbons B₂ is

 B₃ is a steroid-containing group, an organic group having a structureof formula (I-1) or —B₄—B₅—B₆, wherein B₄ is an alkylene group of 1 to10 carbons, B₅ is

 and B₆ is a steroid-containing group or the organic group having thestructure of formula (I-1):

in the formula (I-1), B₇ is a hydrogen atom, a fluoro atom or a methylgroup; B₆, B₉ and B₁₀ respectively are a single bond,

 or an alkylene group of 1 to 3 carbons; B₁₁ is

 wherein B₁₃ and B₁₄ respectively are a hydrogen atom, a fluorine atomor a methyl group; B₁₂ is a hydrogen atom, a fluorine atom, an alkylgroup of 1 to 12 carbons, a fluoroalkyl group of 1 to 12 carbons, analkoxyl group of 1 to 12 carbons, —OCH₂F, —OCHF₂ or —OCF₃; a is 1 or 2;b, c and d respectively are an integer of 0 to 4; e, f, and grespectively are an integer of 0 to 3, and (e+f+g)≧1; i and jrespectively are 1 or 2; when B₇, B₈, B₉, B₁₀, B₁₁, B₁₃ or B₁₄ arepluralities, B₇, B₈, B₉, B₁₀, B₁₁, B₁₃ or B₁₄ respectively are the sameor different:

in the formula (II), B₁₅ and B₁₇ respectively are

 B₁₆ is an alkylene group of 2 to 10 carbons; B₁₈ is asteroid-containing group or the organic group having a structure offormula (I-1).
 2. The liquid crystal alignment agent of claim 1, basedon a total amount of the diamine component (b) as 100 moles, an amountof the diamine compound (b-1) having the structure of formula (I) is 3moles to 40 moles, an amount of the diamine compound (b-2) having thestructure of formula (II) is 10 moles to 40 moles, and an amount of theother diamine compound (b-3) is 20 moles to 87 moles.
 3. The liquidcrystal alignment agent of claim 1, wherein a molar ratio of the diaminecompound (b-1) having the structure of formula (I) to the diaminecompound (b-2) having a structure of formula (II) is 0.1 to
 3. 4. Theliquid crystal alignment agent of claim 3, wherein the molar ratio ofthe diamine compound (b-1) having the structure of formula (I) to thediamine compound (b-2) having a structure of formula (II) is 0.2 to 2.8.5. The liquid crystal alignment agent of claim 4, wherein the molarratio of the diamine compound (b-1) having the structure of formula (I)to the diamine compound (b-2) having a structure of formula (II) is 0.3to 2.5.
 6. The liquid crystal alignment agent of claim 1, wherein animidization ratio of the polymer composition (A) is 30% to 80%.
 7. Aliquid crystal alignment film, formed by a liquid crystal alignmentagent of claim
 1. 8. A liquid crystal display element, comprising aliquid crystal alignment film of claim 7.